Death by the Brain Criterion: A Response to Shewmon

3. Assessing the Significance of Remaining Activities

A difficulty that we have always had in understanding death of the human body is that, in most instances, some living activities persist within the body after death. Some of these can be dismissed as parasitic, such as the bacteria within the gut, though they ordinarily have important functions there. I have had personal experience of the harm that occurs if those bacteria are destroyed by strong anti-biotics. Some activities seem not to be significant, such as hair and fingernail growth. We can even remove a living sperm from a dead man, long after his heart and circulation has ceased, and use it reproductively so that he can father a child posthumously.

It is true that, after loss of all function of the brain in a body maintained to some extent on life support, there is certainly more activity occurring within that body than would occur in a body in which circulation had ceased. The issue is whether this activity is sufficient to provide evidence that the dynamic, intercommunicative unity of the body is maintained in those activities or whether the activities occur in relative isolation and not as a functional or dynamic unity.

As I have indicated, part of the difficulty in relation to Alan Shewmon's assumptions about continuing functions in a body in which all function of the brain has ceased, and consequently the position he has adopted rejecting the brain criterion, is that he is operating in an environment in which the Mode of Being view is dominant. The Mode of Being view was described by the U.S. President's Council17 as the contemporary basis for accepting death by the brain criterion. The Mode of Being view requires interaction with the environment. The Council rejected an integration view of death by the brain criterion and, more importantly, in doing so it set criteria for diagnosing death by the brain criterion that included only irreversible loss of spontaneous breathing and irreversible loss of consciousness, not loss of all brain function. In a way this was a recognition that US medical practice had moved away from what remains the legal definition of death in the U.S.:

An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards.18

Unlike the U.S., the U.K. has actually changed its law to reflect what is now the U.S. Mode of Being view. In 1995, the U.K. adopted irreversible loss of brain-stem function as the legal definition of death,19 thus better reflecting U.K. medical practice that had moved away from testing for irreversible loss of all brain function to testing for loss of brain stem function only.

Establishing irreversible loss of spontaneous breathing and of consciousness, which result from loss of brain-stem function, is a much lesser standard. The latter is certainly not what John Paul II accepted when he explained that the neurological criteria for determining death “consists in establishing, according to clearly determined parameters commonly held by the international scientific community, the complete and irreversible cessation of all brain activity (in the cerebrum, cerebellum and brain stem).”

What is referred to in actual medical practice as “brain death” in the United States and in most English-speaking countries, is now not loss of all function of the brain at all. Loss of consciousness and loss of spontaneous breathing may mean only that there is substantial damage to the brain stem.

There has been a significant change in the diagnosis of death by the brain criterion since I first began in this area, over 30 years ago. At that time, the clinical tests for brain-stem function were used at the end of a process to determine that the assessed damage to the higher parts of brain, usually as a result of brain swelling after trauma, had extended down to include the brain stem. In other words, swelling of the brain, in the rigid container that is the skull, caused loss of blood supply and thus destroyed not only the upper and mid-brain but also the brain stem. The clinical tests for some brain stem functions were thus only confirmatory and not, on their own, determinative.

In August 2012, at the launch of my book, About Bioethics: Vol. III, Transplantation, Biobanks and the Human Body (Connor Court, Ballan 2012), the Vice Chancellor of Monash University, Professor Ed Byrne, a neurologist, supported this interpretation of the changes that had occurred since he and I worked together as fellow department heads at St. Vincent’s Hospital, Melbourne, in the 1980s. At that time, after having death diagnosed by the brain criterion, it was understood that this was not a stable state and heart function would cease within 24 hours. That was such a contrast to what is now described as “brain death”, with some pregnant women even surviving in that state long enough to give birth months later!

Unfortunately, the way in which the criteria are now applied, it is not necessary to have established that all functions of the brain have ceased. It is possible and in fact not uncommon, that the current criteria being applied in English-speaking countries permit the diagnosis of death, according to the Mode of Being view, on the basis of damage to the brain stem alone, which would result in irreversible loss of consciousness and irreversible loss of spontaneous breathing, but not always loss of all brain function.

Alan Shewmon has reported a case in which homoeostasis was maintained in a patient who had been diagnosed according to the criteria applying in the U.S. for diagnosing death. The Pontifical Academy of Sciences did not accept Shewmon’s claim in that respect,20 but it should be borne in mind that the panel was comprised mostly of Europeans and the widely accepted European practice is not the Mode of Being view, but loss of function of all parts of the brain.21 Homeostasis cannot be maintained in that state, which is partly why, thirty years ago, loss of circulation followed death by the brain criterion within 24 hours. The practices I have observed in Europe involve using ancillary testing to determine that there is no blood supply to the brain. That does establish with some certainty that there is loss of all brain function because warm brain tissue dies quite rapidly if deprived of oxygenated blood. Shewmon’s context, what he would understand is meant in practice is death determined by the brain criterion, is not what Pope John Paul II described as death by the neurological criteria. The latter clearly reflected a quite different practice from the current U.S. practice, the so-called Mode of Being view or what, in the law of the U.K., is now accepted as the death of the brain stem alone. We have the same problem in Australia and New Zealand with the leading authority, the Australia and New Zealand Intensive Care Society (ANZICS), describing the determination of death by the brain criterion as being diagnosable by the clinical tests for brain-stem function and at the same time admitting to continuing functions that are brain mediated functions.22

The ANZICS position is odd. On the one hand, the document states:

Brain death cannot be determined without evidence of sufficient intracranial pathology. Cases have been reported in which the brain-stem has been the primary site of injury and death of the brain-stem has occurred without death of the cerebral hemispheres (e.g. in patients with severe Guillain-Barré syndrome or isolated brain-stem injury). Thus brain death cannot be determined when the condition causing coma and loss of all brain-stem function has affected only the brain-stem, and there is still blood flow to the supratentorial part of the brain. Whole brain death is required for the legal determination of death in Australia and New Zealand. This contrasts with the United Kingdom where brain-stem death (even in the presence of cerebral blood flow) is the standard.23

On the other the document allows for the diagnosis on the basis of the clinical tests without ancillary testing to rule out middle and upper brain function, and it affirms that the following activities may continue in someone diagnosed by the clinical criteria (brain-stem) alone:

sweating, blushing, tachycardia;

normal blood pressure without the need for pharmacological support; and

17. President's Council on Bioethics, Controversies in the Determination of Death: A White Paper (January 2009), Accessed December 2009 from http://bioethicsprint.bioethics.gov/reports/death/index.html.

18. Uniform Determination of Death Act, Accessed 9 February 2009 from http://www.law.upenn.edu/bll/archives/ulc/fnact99/1980s/udda80.htm.

19. “Criteria for the Diagnosis of Brain Stem Death,” Journal of the Royal College of Physicians 29 (1995): 381-82.